The research concerns the movement of materials across the intestine of the parasitic roundworm Ascaris suum. It involves determinations of 1) the transport of ions, sugars, and amino acids across the intestine; 2) the ability of the basement membrane to function as a diffusion barrier; and 3) the mode of action of the anthelmintic drug, mebendazole, upon the transport of non-electrolytes by the intestine. BIBLIOGRAPHIC REFERENCES: Beames, C.G., Jr., Merz, J.M. and Donahue, M.J. (1976) Effect of Anthelmintics on the short circuit current of the intestine of Ascaris suum. In Biochemistry of Parasites and host-parasite relationships. Ed. by H. Van den Bossche. Elsevier/North-Holland Biomedical Press-Amsterdam. p. 581-587. Beames, C.G., Jr., Merz, J.M. and Donahue, M.J. (1977). Solute and Water Movement in the Roundworm Ascaris suum (Nematoda). In Water Relations in Membrane Transport in Animals and Plants. Ed. by A.M. Jungreis, T.K. Hodges, A.M. Kleinzeller and S.G. Schultz. Academic Press, p. 97-109 (In press).